Commission just doing its job: Brandis

Attorney General George Brandis says despite all the furore over last week's police raids on the offices of the Australian Workers Union, the Registered Organisations Commission has to enforce the law when it believes it has been breached.

The independent commission is pursuing whether there was a breach of union rules in 2006 when Bill Shorten, then leader of the AWU, arranged for a large donation be paid to activist group GetUp!.

"Its job is to enforce the law and if it finds the law has been breached, then its obligation is to pursue that," Senator Brandis told Sky News on Sunday.

However, Labor is still not happy with Employment Minister Michaelia Cash's account of events which saw the media tipped off about the raids.

She denied five times during a Senate hearing she had nothing to do with it, only to later confess it was a person in her office who had done it and had subsequently resigned.

Manager of Opposition Business Tony Burke cannot accept that before the confession Senator Cash told Prime Minister Malcolm Turnbull that no one from her office was involved when her staff were in the room with her.